Michael Ballack ensured Chelsea kept their date with Manchester United for the first FA Cup final at the new Wembley on a heartbreaking afternoon for Blackburn at Old Trafford on Sunday.

The Germany captain's strike, four minutes into the second period of extra-time, was enough to give his side a 2-1 win and keep alive their dream of a clean sweep of all four tournaments they have entered this season.

But it was a close-run thing for Jose Mourinho's men, who almost paid a heavy price for their failure to make more of early dominance and had reason to be grateful for a man-of-the-match performance by goalkeeper Peter Cech.

After Jason Roberts had cancelled out Frank Lampard's opener, Blackburn might easily have claimed victory in the closing stages of regulation time, when their Norwegian winger Morten Gamst Pedersen directed a free header wide from barely six yards out.

Instead, it fell to Germany's captain to settle the contest, sweeping the ball home from 12 yards after Stephen Warnock had blocked Saloman Kalou's attempt to get on the end of Shaun Wright-Phillips's cutback from the byline.

Mourinho was relieved to have seen off Blackburn's spirited challenge and he said: "It is a very special feeling because the game was amazing. It was the kind of game when you win you are crazy with happiness, but you have a lot of feelings for the other team.

"They fought like heroes like we did. Normally heroes are only the winners, but I have good feelings for them because they were amazing."

Mourinho insisted the prospect of facing United in showdowns for the Premiership and now the FA Cup underlined how good both teams have been this season.

"It is a big, big final. It is a final between first and second in the Premiership, it is final between two semifinalists in the Champions League.

"Independent of what happens for the rest of the season, we could win everything, they could win everything or even if we both win nothing, Chelsea and Manchester United are two unbelievable teams."

Blackburn manager Mark Hughes was convinced his team had done enough to win and he said: "We deserved to go through today. In the second half we were outstanding and there was only one team that tried to affect the game.

"We showed real belief and that was the key. They are an exceptional team but we made them look ordinary today. Their keeper was oustanding and that tells the story."

Cech added: "We never give up. We always believe we can make it in the last seconds and we did the same today.

"Blackburn had to come with everything to try to score. They made a great effort in the second half and deserved to equalise. But we showed our character becase we never gave up when it was 1-1."

Hughes's decision to opt for Roberts in attack at the expense of the more lightweight Matt Derbyshire suggested a belief that Chelsea could be bludgeoned into conceding chances.

Instead it was Chelsea's superior cutting edge which provided the dominant theme for most of the first half.

The first clear sight of goal fell to Ashley Cole, who forced a good save from Brad Friedel after combining with Joe Cole, who was making his first start since November.

By that stage, a Chelsea opener was beginning to look inevitable. But it still required errors from both Blackburn centrebacks to allow them to take the lead with just over quarter of an hour played.

First Christopher Samba allowed Drogba the time to bring Peter Cech's goal-kick under control and lay the ball off to Ballack.

Then, when the Germany captain rolled a pass through the inside right channel, Ryan Nelsen's ill-judged lunge at the ball allowed Lampard to nick the ball past him before sweeping a low shot beyond Friedel's right hand and into the bottom corner of the net.

Joe Cole went close to adding a second soon afterwards when he smoothly gathered Drogba's chested lay-off on the edge of the area and unleashed a fierce half-volley that flew fractionally over the target.

Blackburn finally came to life in the final minutes of the opening period.

Ricardo Carvalho did well to snuff out the danger when Benni McCarthy chested a David Bentley cross down just beyond the back post.

It then required a fine save from Cech, diving to his left, to keep out a drive from Dunn that would have been just reward for the midfielder's efforts to galvanise his team-mates.

Samba got his head to the resulting corner from Morten Gamst Pedersen but was unable to direct his effort below the bar.

That flurry hinted at the sustained fightback that was to materialise after Andrei Shevchenko had comically squandered a glorious opportunity to double Chelsea's lead barely a minute after the restart.

Another fine Ballack pass released Drogba on the right and when the Ivory Coast striker squared the ball towards the unmarked Ukrainian close to the penalty spot, a second goal appeared a formality.

Instead, Shevchenko contrived to fluff his right foot shot so badly that the ball cannoned into his standing leg.

Blackburn immediately set about exploiting that let-off. Roberts forced Cech into another good save at his near post and Pedersen saw a header from a Bentley cross come back off the post before they deservedly got back on level terms after winning a freekick on the right of the Chelsea area.

Pedersen's delivery was driven low towards the centre of the goal and Roberts managed to get in front of his marker John Terry and get enough of a contact on the ball to deflect it wide of Cech's left-hand.

With the game opening up, there were half chances at either end but it was Blackburn who went closest to settling the contest in their favour inside the 90 minutes.

After Pedersen had directed another superb Bentley cross wide with seven minutes left, Chelsea had another narrow escape only 90 seconds from the end of regulation time, when Cech clawed the ball to safety after substitute John Obi Mikel's back header had sent a long throw-in spinning towards the top corner of his own goal.

Chelsea midfielder Michael Ballack exults in joy after scoring the winner in extra-time during their FA Cup semifinal clash against Blackburn at Old Trafford in Manchester on Sunday. PHOTO: AFP